This is the latest edition of an important U.S. Army field manual (FM) covering the support required on the battlefield by theater area commands. Some highlights of the contents: "FM 100-5, the Army"s keystone doctrinal manual, explains the Army"s operational concept for the air-land battle. This manual gives the basic doctrinal background on which all other doctrinal manuals are based. In its explanation of the air-land battle, FM 100-5 emphasizes the terms initiative, depth, agility, and synchronization as being the basic tenets for success on the modern battlefield. These terms apply to combat support and combat service support elements as well as to combat forces. Inherent in these terms is an understanding between all commanders, supporting and supported, subordinate and senior, vertical and lateral, of the overall mission and the plans to accomplish it. Subordinates must clearly understand the intent, as well as the details of the overall commander"s plan. This allows them to deviate from the details when the situation demands or when an opportunity to hasten the execution of this intent presents itself. SUPPORT - The modern battlefield poses great challenges, not only to the combat and combat support forces, but also to the CSS units that must sustain the forces. US forces must get the most out of what they have. Every conceivable logistics asset must be used. CSS planners and operators must possess the same leadership qualities as combat leaders in order to effectively support the overall tactical plan. The CSS force must make use of the principles of responsiveness, flexibility, and initiative. The changing situations that will be met on the battlefield require that CSS commanders foresee needs before demands are placed upon them. The commander of the Leaders at all echelons and of all the force elements must be able to think faster, make decisions more rapidly, and act quicker than the enemy. All efforts must be synchronized so that the parts of the force may combine quickly and powerfully at the most opportune point and time. CSS elements are an indispensable element of massing at the critical point and time. The weight of support must be added to the weight of combat power. They are inseparable. Success on the battlefield will require many changes in attitude and training methods. Initiative and innovation must be stressed, and an aggressive spirit must permeate US forces. All training must be as close as possible to anticipated conditions on the modern battlefield. These conditions include environment, tempo, and the dimensions of time and space. Teamwork, flexibility, and initiative must always be emphasized in training programs." It is fully illustrated with numerous line drawings.